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1.
-Spermophilus brunneus . , 13 18 ,S. brunneus S. townsendii mollis (2n=38) , , ; ;S. brunneus . S. brunneus , Spermophilus.

Supported by National Science Foundation Grants No. GB32114X and No. GB 29131X, and the Sprague Foundation. We thankD. Pozin for technical assistance.  相似文献   

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This work was supported by a Rackham Grant from the University of Michigan.  相似文献   

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Summary The new methods for the production of 19-norsteroids described involve the conversion of 5-halogen-6-hydroxy-steroids into the corresponding 5-halogen-6:19-ethers either with lead tetraacetate or by the hypoiodite reaction8,10. The 6:19-oxygen bridge is then opened reductively either directly or after oxidation of the 6:19-ethers to lactones or preferably after introduction of a 4,6-3-oxo grouping. Acylolytic cleavage of the 4-3-oxo-6:19-ethers followed by alkaline hydrolysis gives 4,6-3-oxo-19-hydroxy-steroids. The 19-hydroxycompounds formed are easily converted into 19-norsteroids by known methods.

Über Steroide, 189. (vorläufige) Mitteilung; 188. Mitt. vgl.J. Kalvoda, J. Schmidlin, G. Anner undA. Wettstein, Exper.18, 398 (1962).  相似文献   

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Conclusions The decrease of circulating blood volume, resulting in oligemic hypotension, may evoke in anaesthetized cat the active constrictory coronary vessel responses of 2 types, one occuring immediately after start of the hypotension and the other having a significantly prolonged latency.
, , , , ( 4 ), ( 45 ).
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Summary During the development of anthers inTulipa cv. Apeldoorn the following chalcones were isolated: 2, 3, 4, 4, 6-pentahydroxychalcone as the main component and 2, 4, 4, 6-tetrahydroxy-3-methoxychalcone as well as 2, 4, 4, 6-tetrahydroxychalcone in a very small amount.

Die Untersuchungen wurden mit Mitteln der Deutschen Forschungsgemeinschaft unterstützt.  相似文献   

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Summary The male antifertility agent -chlorohydrin (I) is metabolized by rat and boar sperm to -chloroactaldehyde (III), -chlorolactate (IV) and Cl and not to the proposed active metabolite, -chlorohydrin-1-phosphate (III). It is proposed that -chlorolactaldehyde is produced intracellularly by a specific enzyme and that this is the metabolite responsible for the species-specific antifertility activity of -chlorohydrin.This work was supported by The National Health and Medical Research Council of Australia.  相似文献   

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Summary 11-(R)-2H porphobilinogen, stereospecifically labelled with deuterium in the aminomethylene group has been incorporated into protoporphyrin-IX by haemolysates of chicken erythrocytes. High field NMR spectroscopy confirms that the overall biochemical process is stereospecific, deuterium being retained at the -, -and -meso positions and lost from the -meso position.27 August 1986  相似文献   

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Summary Photorefractory male yellow-throated sparrows (Gymnorhis xanthocollis) were subjected to six resonance light cycles, consisting of 6 h basic photophase coupled with scotophases of longer durations (in cycles of 12 (6L6D) h, 24 (6L18D) h, 36 (6L30D) h, 48 (6L42D) h, 60 (6L54D) h and 72 (6L66D) h). Termination of photorefractoriness was evident in cycles of 24, 48 and 72 h, but not in 12, 36 and 60 h. The results are consistent with the external-coincidence model (Bünning hypothesis) and suggest that endogenous circadian rhythmicity is involved in the termination of photorefractoriness.To whom reprint requests should be addressed.This investigation was supported by a UGC grant to PDT and BHU to PMT.  相似文献   

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Zusammenfassung Es wurde der Hemmungseffekt von Colcemid und Vincristin auf die Méiose bei Mäuseeiern in vitro und in vivo untersucht. Die in vitro wirksame minimale Konzentration für Vincristin wurde bei 4×10–7 g/ml, für Colcemid bei 4×10–3 g/ml gefunden. Die in vivo wirksame Minimaldosis von Vincristin war 1 g/g. Körpergewicht, von Colcemid 10 g/g Körpergewicht.

Part of this data was presented in abstract in Clinical Research, vol. XV, No. 2, April 1967, p. 268.  相似文献   

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Summary Investigating the slow positive potentials of the electroretinogram (ERG) of different mammals, c-wave and d.c.-potential proved to be strictly discernible. With respect to its amplitude and its peak time, the c-wave differs in various species. There are two types of d.c.-potentials, a scotopic and a photopic one.  相似文献   

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Summary Kinetics studies of haemolymph -glucosidase inhibition by D. glucose led to general correlations between inhibition and control parameters, all over the honeybee development. Maximum velocities are not affected by the inhibition, while affinity constants are always significantly increased, and Hill coefficients tend to decrease, especially in foraging adults and in prenymphs. In this later case, the n-type effect tends to break the manifestation of the K-type mechanism.  相似文献   

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